Ingersoll Rand ~ IR type 30 4 and 2 1/2 x 2 1/4 air blowing off

by Phil

Ingersoll Rand T30 air compressor

Ingersoll Rand T30 air compressor

IR type 30 4 and 2 1/2 x 2 1/4

Serial No TP95442 L15
This machine has a 4kW (5.4 hp) 3 phase 1420 rpm motor with a 9" dual V motor pulley. It pumps very well and quickly reaches 100 psi (set to trip @ 140psi) then slows down along with a release of compressed air from around a small pipe that goes into the crankcase between the V cylinders. Pump has plenty oil and seems free. Any ideas before I run a current test on the motor to look for shorted windings etc.

I can't see where the air is discharging, Phil. I suspect that it's a PRV blowing off, and that's suggesting that something downstream of it is cause an air dam or back pressure, pressure builds in the line between cylinders, and the safety release goes.

I'd be looking, therefore, at the second cylinder for issues, before I'd look to the motor.



Comments for Ingersoll Rand ~ IR type 30 4 and 2 1/2 x 2 1/4 air blowing off

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May 10, 2013
by: Anonymous

I am rebuilding my T30 model 253. I used a puller to get the flywheel or pulley of the compressor head. It did not come off easy. The question that I have is: How do I get the pulley back on? Do I have to drive a wedge in the split of the pulley? Or is there another trick?

Jun 11, 2011
IR type 30
by: Phil

Right, I have serviced the non return valve, didn't appear to be a lot wrong with it, but it is perfect now, checked HP and LP valves, all ok. H ave rewired the pressure switch to control the starter relay rather than break all three phases. Noticed thaty the pressure switch is only rated at 6 Amps and the motor is 8.7 FL amps. Looks like that could have been the problem as the switch contacts were quite badly burnt. It now seems to be working much better although I still have reservations about the motor. I used the shotgun approach as time on the job was limited, and it seems to have worked in this case. Unloader valve is also functioning correctly now. Thanks Bill,



Jun 04, 2011
Ingersoll Rand type 30
by: Phil

Hi Bill, thanks for your comments. They make a lot of sense when I think of the symptoms as they happen! It does sound like the HP cylinder is loading up with back pressure from the tank. The PRV that appears to be blowing off is a pipe connected at one end to the output manifold of the HP cylinder, and the other end appears to join the crankcase between the specification plate and the oil filler/level plug. I will post you a picture if I can work out how to do it!

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